Feature Article

Native Landscaping for Biodiversity

Removal of invasive plants and support of native plantings are critically important for maintaining healthy ecosystems.

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As I’ve stepped back from BuildingGreen in recent years, I’ve shifted more of my time and energy to restoring ecological balance to the Dummerston, Vermont, property where my wife, Jerelyn, and I live. This has meant doing battle with a wide variety of invasive plants—especially oriental bittersweet, Japanese barberry, bush honeysuckle, glossy buckthorn, multiflora rose, burning bush, and Japanese knotweed—as well as nurturing a diversity of native plants. I have somehow known that this was important, but until coming across Professor Doug Tallamy’s books, I didn’t understand the full ecological significance of these efforts.

With this report, Paula and I want to share with our readers this newfound understanding—and especially the important role architects, landscape architects, and developers can play in supporting and enhancing biodiversity in the landscapes around our buildings.

–Alex Wilson

The Importance of Biodiversity

Google campus Charleston Retention Basin

The Charleston Retention Basin on Google’s Mountain View campus is a six-acre wetland supporting native plants and inviting humans to enjoy it on a nature trail. (Photo courtesy Google Ecology Program)

It may take hundreds or thousands of years to return to pre-industrial-age levels of atmospheric carbon dioxide, but the loss of animal and plant species that is occurring today is, practically speaking, irreversible. It will take millions of years for evolution to fill the ecological niches being vacated by extinctions and restore healthy ecological balance.

A 2020 report published in the Proceedings of the National Academy of Sciences by Gerardo Ceballos, Paul Ehrlich, and Peter Raven, Vertebrates on the Brink as Indicators of Biological Annihilation and the Sixth Mass Extinction, brings the significance of species extinctions and loss of biodiversity into focus. Ehrlich is quoted in an article in The Guardian about the report as saying that “the conservation of endangered species should be elevated to a global emergency for governments and institutions, equal to the climate disruption to which it is linked.”

“We can’t lose [biodiversity] and still continue on this planet,” says Douglas Tallamy, Ph.D., an entomologist who has written several books about the importance of native landscapes to the food web. “The really sad part is that nobody knows that. We think we’re separate from nature, but nature produces the life support systems that keep us around.”

This report explores what architects, landscape architects, and developers can do to support biodiversity and explains why supporting native plants has become one of the greatest tools in the arsenal.

Nature Preserves

A key priority for retaining healthy biodiversity is to maintain large tracts of unbroken, contiguous natural area. However, we’re nowhere close to that ideal if one looks at the amount of land currently in preservation.

E.O. Wilson argues in the 2016 book Half Earth that to preserve the biodiversity that the Earth depends on (saving roughly 85% of animal and plant species), we really need to set aside 50% of the world’s land area. Experts worldwide have latched on to this broad-brush goal.

According to a recent United Nations report on climate change and biodiversity, only 15% of the world’s land area is currently under some level of protection—as national parks, forest preserves, private nature preserves, etc. (defined as Class 1 and Class 2 in the U.S. Geological Survey categorization of protected areas). Currently, the U.S. has between 12% and 13% of its land area in permanent Class 1 and Class 2 protection. Only Bhutan, a small Himalayan monarchy wedged between India and China, has achieved Wilson’s desired level of land conservation—with 52% of its land area set aside in parks and conservation reserves.

For most of the rest of the world, including the U.S. and Canada, protecting half of the land area will be extremely difficult to achieve. So if we accept the idea that protecting the biodiversity we depend on will require more land than is found in large unbroken tracts, then we also need to look to smaller, privately owned parcels of land for achieving ecosystem health. Then we need to connect those parcels via wildlife corridors that afford animals safe passage from one place to another—allowing genetic diversity to be maintained in species. That’s where we as architects, landscape architects, and developers can play such an important role.

Glenstone museum meadow approach

The approach to the Glenstone Museum includes a four-minute walk through this meadow.

Photo: Iwan Baan
“Parks and preserves are central to any large-scale conservation effort,” writes Tallamy in the book Nature’s Best Hope, “but they will never be enough, because they are not large enough and they are not connected to one another.” Tallamy argues that we also need to create healthy ecosystems in the landscapes around our buildings. “The solution is a grassroots solution,” Tallamy said in an interview with BuildingGreen. “Everybody who owns a little piece of the Earth … I’ve got to talk to everybody.”

Why Even Small Patches of Natural Area Can Support Biodiversity

While large, unbroken tracts of natural area are critical for a wide range of fauna and flora, even very small tracts of natural area in cities or the suburbs can support a surprising array. A single native oak tree can serve a vital role in supporting insect herbivores, which constitute a critical building block of the food web. Many cities host more native bees and other species than the surrounding agricultural areas, due in part to widespread pesticide use in agricultural areas. Others might not be able to support many permanent residents but provide enough food for migratory species like butterflies and birds to sustain themselves as they pass through.

Then there’s the fact that even small parcels can be ecologically unique. Cities are “built in non-random places—arguably the best places ecologically,” like rivers and estuaries, according to Robin Grossinger, Ph.D., coauthor of Making Nature’s City. These “lost ecosystems ... can only be restored in those areas,” he told BuildingGreen.

“Ecology in cities can’t replace ecology in the reserves and bigger wild spaces around cities,” Grossinger continued. But we still need the cities to perform ecologically,” he said.

Native Plants and the Food Web

On smaller parcels, supporting native plantings is probably the single most impactful strategy for boosting biodiversity. There are three sources that have brought, or are continuing to bring, non-native plants into our landscapes, according to Neil Diboll of Prairie Nursery in Westfield, Wisconsin. First, herbaceous weeds were brought by European colonizers with hay on ships, used for feeding livestock they brought to the New World. Second, many of these plants were introduced by the nursery trade as ornamentals, and without insects that eat them, then escaped into the wild and became invasive. Other non-natives were, ironically, introduced by government agencies as sources of wildlife food (autumn olive and honeysuckles, for example). According to other sources we spoke with, still others were introduced accidentally as seeds in packaging material or hitchhikers on imported ornamentals. Surprisingly, the net result of all these non-natives is a dramatic loss of food for insect herbivores and the ecosystems that depend on those insects.

High Line maintenance crew NYC

Gardening staff work hard to keep invasive plants out of the High Line plantings. During a several-minute walk on the High Line in mid-June, 2014, entomologist Doug Tallamy spotted four different pollinator bees foraging on butterfly weed, and he saw three Monarch butterflies—the first he had seen anywhere in the East that year.

Photo: Alex Wilson

To understand why, it’s important to look at how plants produce carbohydrates and how insect herbivores convert that plant tissue into high-protein food for a variety of birds and other wildlife.

We were all taught that sunlight fuels the remarkable process of photosynthesis in green plants, through which carbon dioxide and water are converted into glucose. Nearly all life on earth, including human life, depends on photosynthesis, either directly or indirectly, to survive. We eat plants directly, in our salads and grains, and many of us eat eggs and meat products that were derived from livestock feeding on grass, forage, and grains.

The world’s food web starts with photosynthetic plants, and it depends on animals being able to eat and digest that plant material. Cows and other ruminants have multiple stomachs that contain bacteria able to break down cellulosic material. Insect herbivores depend on particular enzymes in their digestive systems to digest plant matter—and therein lies the rub.

Most plants have evolved various defenses to protect them against insect herbivores. Plants in the milkweed family contain toxic cardiac glycosides in their milky sap that are poisonous to most insects (as well as to humans). Other plants contain alkaloids, such as nicotine and morphine, that protect the plants from many herbivores.

For insect herbivores to be able to eat plants that include toxins, those insects have to co-evolve with the plants. Monarch butterflies, for example, co-evolved with milkweed, with the larval caterpillars evolving enzymes to detoxify the glycosides so that the plant tissue can be consumed. The same process exists with many other caterpillars: they are highly specialized and can only eat very specific plants. “Insect herbivores can only eat plants when they neutralize the plant’s defenses,” Tallamy told BuildingGreen. In a balanced ecosystem, insect herbivores like caterpillars eat their host plants, and many of those caterpillars, in turn, nourish growing birds, amphibians, rodents, and other animals.

High Line native plantings NYC

The High Line on the west side of Manhattan is a mile-and-a-half section of elevated rail spur that was converted into a linear park with native plantings. The collaborative design was by James Corner Field Operations, Diller, Scofidio + Renfro, and Piet Oudolf.  Here we see butterfly weed amid a wide assortment of native grasses and forbs.

Photo: Alex Wilson

A problem occurs when we introduce non-native plants. First of all, because those plants typically don’t have insects in their new home that are able to digest the plants, they grow unchecked—becoming invasive in the environment. This is what we are seeing throughout much of the U.S., where a wide variety of non-native, invasive plants are out-competing native plants and exploding in population. The problem starts when you think of your landscape as purely ornamental, Tallamy explains. Just as “you can’t build a house out of wallpaper,” you can’t build a habitat out of non-native plants. “Crepe myrtle is not going to spread, but when it’s 75% of the biomass in your yard, we’ve got a failed food web.”

Second, this is a problem because those non-native, invasive plants don’t serve as a food source for insect herbivores, so those insects find little to eat. Insect populations drop, and the animals that feed on those insects, in turn, can’t find enough to eat.

It is important to distinguish the pollinator role played by many insects and the role the same (and other) insects play as primary consumers of plant matter. A lot is said of the critical role pollinators play in a healthy ecosystem. The vast majority of flowering plants, some 90% according to Tallamy, rely on insect pollinators to fertilize flowers. We are learning to plant pollinator gardens and buffer strips to support these pollinators, which are usually flying insects that are harvesting nectar from plant flowers.

But it is often a more important role that plants play in feeding the larval stages of insects—such as caterpillars. Some plants, such as butterfly bush, are great at feeding butterflies in our pollinator gardens but inedible to the larval stages of our native insects. Butterfly bush (not to be confused with the native butterfly weed) is a non-native plant that virtually no larval insects consume, though the nectar from its flowers is consumed by many insects.

Even among native plants, there is a big difference in how important various species are as a food source. Among trees, oak trees are host to more insect herbivores than any other genus of tree. According to Tallamy, oak trees serve as a food source for larvae of a remarkable 511 species of butterfly and moth. Those caterpillars, in turn, feed the songbirds that serenade us in the mornings and brighten our days. Tallamy told BuildingGreen that it takes 6,000 to 9,000 caterpillars for a chickadee to feed her brood of young. Without that food source, songbirds will nest elsewhere, or not nest at all.

Other Benefits of Native Landscapes

The ecological benefits of native landscapes are huge, but there are other benefits that, for some, will be even more important. Compared with conventional turf-and-mound landscaping (lawn area punctuated by trees or shrubs growing out of mounds of sterile mulch) that is ubiquitous around office parks, manufacturing facilities, hospital campuses, and homes, native landscapes offer a wide range of environmental and economic benefits. Ecologically, turf is “a dead zone,” says Tallamy, yet the U.S. alone hosts 40 million acres of it—an area the size of New England.

Avoiding irrigation—By their very nature, native plantings are adapted to the local climate, and it’s possible to select those that are climate resilient as well. Most natives will not require irrigation—which often accounts for roughly a third of residential water consumption in the U.S. Native plantings in Phoenix will consist of cactus and include lots of bare ground. In the Midwest, one could expect prairies, while woodlands and meadows may make sense in the east. None of these native landscapes should require irrigation, though it may be necessary to provide some irrigation as native plantings are established. (It’s important to note that with climate change, droughts are becoming more severe and there are places where even native species will be unable to survive without irrigation.)

Eliminating fertilizer—Except in rare cases where brownfields or urban lots are being restored, fertilizers should not be required in establishing and maintaining native landscapes. This will not only save money but also avoid nutrient runoff—one of the leading causes of water pollution in the U.S.

A pond in the backyard of Drew Lathin.

Landscape designer Drew Lathin created a pond with native plantings by diverting his sump pump drainage away from a sewer grate.

Photo: Drew Lathin

Reducing the use of pesticides—Large quantities of herbicides, insecticides, and other pesticides are used today for maintaining conventional lawns. These pesticides are typically applied at 20 times the rate used by farmers per acre, according to the U.S. Environmental Protection Agency (EPA)! As described below, however, judicious use of herbicides can play an important role in the removal of invasive plants in woodlands and other landscapes when native landscaping is being re-established.

Eliminating or reducing the frequency of mowing and other landscape care—According to the EPA, gasoline-powered landscape equipment, including mowers, leaf blowers, power trimmers, etc., accounts for more than 5% of urban air pollution—not to mention the cost of the equipment and labor to operate it.

Increased infiltration—EPA claims that a lawn has “less than 10% of the water absorption capacity of a natural woodland.” Lawn area, therefore, isn’t as effective at filtering pollutants and recharging aquifers, and—very significantly with climate change—it will contribute more to flooding during extreme rain events.

Saving money in landscape management—In most cases, after establishing native landscapes, the cost of maintaining them is a lot less than maintaining more conventional turf and manicured plantings. Keson Industries has saved roughly $75,000 since the conversion of four acres of turf to native prairie in 2006, and the initial investment had a 3-1/2-year payback (see case study).

The Human Role in Creating—and Solving—the Problem of Invasive Plants

Since humans have introduced the non-native, invasive plants that increasingly plague our landscapes, we need to lend a helping hand to restore a more balanced ecosystem. That’s where those of us managing landscapes around our buildings need to play an important role.

There are some superb examples of invasive plant removal and ecosystem restoration using 100% organic methods, without the use of herbicides (see the case studies on Glenstone Museum and Google’s campuses), but many more projects rely on herbicides to achieve the same end more affordably and quickly.

Jack Pizzo, of Pizzo & Associates, Ltd., describes himself as a landscape architect turned ecologist. His firm of 90 in Leland, Illinois, is a natural area restoration and management company that has worked in 17 states, as well as a native plant nursery that produces planting stock for its projects. Having been involved in many hundreds of projects that involve reestablishing native landscapes, he deals with invasive plant removal all the time.

Glenstone museum water court

Visitors to Glenstone are invited to view this native wetland from inside the museum.

Photo: Iwan Baan

“If you study the way that native plants and invasives interact,” Pizzo told BuildingGreen, “this is not about making native plants grow; it’s about making invasive species not grow.” The company uses every means possible to kill invasive plants. “Our goal is always to get to no chemical use,” says Pizzo, “and we have lots of sites where we’ve done that.” But the company also relies heavily on herbicides, primarily glyphosate (best known under the brand name RoundUp). Used properly, according to Pizzo, glyphosate degrades incredibly fast in the environment. “There are so many species we can’t kill without it.”

Diboll echoed Pizzo’s attitude on herbicides. “I used to be totally organic,” he told BuildingGreen, “until I needed to get something done.” Diboll reads the scientific papers on health and environmental impacts of herbicides, including EPA toxicology reports and studies from Health Canada (which he particularly values), and he makes decisions about herbicide selection accordingly. “There are many herbicides I wouldn’t touch with a ten-foot pole,” he said. Like with others we spoke with, glyphosate is usually his herbicide of choice.

Long View Forestry, an employee-owned regional company based in Westminster and Hartland, Vermont, has a woodland management division that deals extensively with invasive plant control. Tom Groves, a botanist who heads up the woodland services division of the company points out that invasives have gotten worse, in part, because the seed bank builds in the soil, and some seeds survive for decades. When there’s a disturbance, those seeds germinate.

According to Groves, control strategies for invasives depend on scale. “If you have little seedlings on a quarter-acre, you can hand-pull easily,” he told BuildingGreen. With mostly woody invasives, they will sometimes mulch the area (using a heavy-duty grinding/mulching head on a skid-steer and leaving the resulting mulch on the ground) without disturbing the soil and releasing the seed bank. With larger parcels where herbicides are used, they may implement a multi-year plan with mulching in year one, herbicide treatment of sprouted invasives in year three (when the plants are at an optimal height for treatment), and then selective treatment of remaining invasives after that.

The concentration and formulation of the herbicide is very important for both safety and efficacy. With cut-and-daub treatment, in which woody invasives are cut and the remaining stump daubed with herbicide, the concentration is quite high, but the chemical is highly targeted. With foliar sprays, a much lower concentration is used, and a surfactant is added to enable the herbicide to penetrate the waxy coatings on leaves. Workers will either use backpack sprayers or ATV-mounted sprayers where invasives are dominant in the understory. Around wetlands, Groves typically uses Rodeo, a brand of glyphosate that is safer for wetland ecosystems.

A key take-away from discussions with Groves is that effective, safe control of invasives requires careful analysis of the site and tailoring of the treatment to those conditions. It is not a haphazard process. Projects where Long View has done invasives control bear this out. On the Riverstone Preserve in Brattleboro, Vermont, areas that were 80%–90% invasives in the understory five years ago are now virtually free of invasives, with native plants regaining footing in the ecosystem.

Checklist for Creating Native Landscapes and Enhancing Biodiversity
Source: BuildingGreen, Inc.

Final Thoughts

Creating native landscapes around our commercial buildings and homes can be a win-win for the environment as well as the property owners. Native plants—but not most invasive plants—support the insect herbivores that play such a crucial role in the ecological food web that our songbirds and so many other animals depend on.

They also provide restorative spaces for humans. “You need some patience, but once you get there, I see how people respond to these landscapes,” notes Larry Weaner, owner of Larry Weaner Landscape Associates in Glenside, Pennsylvania. “It’s really different from the way people respond to a traditional landscape.” Weaner said he used to talk about easy management, environmental benefits, and aesthetics when discussing native landscapes. Now, instead of aesthetics, he talks about experiences. “There are many additional dimensions than just what it looks like that people really respond to,” he said, especially the birds, insects, and other wildlife that inhabit these spaces.

Be aware that, as with many sustainability goals, it’s important to start early with native landscaping. Because it’s not about how to fit the landscape in around the buildings, says Grossinger. It’s about how to most effectively landscape on the site and then figure out where the buildings can go. “Having ecology be there at the beginning of the process and be part of all the different steps is part of the key, whether it’s a master plan or building plan,” he argues. “You’re looking at the site and the neighborhood in a completely different way” because ideally you’re becoming part of a “network of nature” rather than just putting in some native plants and expecting an ecosystem to appear.

Case Study: The Art of Native Landscaping

Glenstone Museum; Potomac, Maryland

The experience begins a half-mile before you arrive: a native woodland and small meadows along the road start preparing you for the forthcoming immersion. Even parking—which happens in “parking groves” instead of on asphalt lots—is part of the deal. Then it’s a four-minute walk over a restored stream and through a meadow before you get to the main museum pavilions. (Accessible options are available.) Surrounding the buildings are 300 acres of native-landscape-cum-sculpture-park.

Glenstone museum boardwalk

This is one of many trails alongside native plants at Glenstone that nourish the human spirit. 

Photo: Iwan Baan

“The landscape design was really meant to bring together art, architecture, and nature within one holistic conception that’s ... really there for people to transition from where they spend their normal, everyday time,” said Adam Greenspan, design partner at PWP Landscape Architects, of Berkeley, California. The team wanted to “create a place where we allow [visitors] to focus on these topics: art, culture, architecture, and nature.”

Radical rethinking

Providing this experience wasn’t easy. The site began as a suburban subdivision with nine homes already built. These were demolished. The grading had to be redone since it had been engineered for single-family homes with their own septic fields.

“What we really focused on was how water flowed over the site and how it could flow over the site,” Greenspan told BuildingGreen. “What we proposed then was that we would re-form the site so it was a much smoother transition of grades” that would “flow more naturally.”

Perhaps most remarkable was the great tree transplant. Two hundred existing trees, up to 36 inches in diameter, were moved around the site “so they worked to highlight the scale of the property and there was some order to the way species were grouped, with combinations of species used together. Then we added about 1,500 trees.”

That was in 2006. Later, after the museum foundation acquired more land, PWP came back and planted 8,000 more trees. Aside from providing pleasure for humans, one of the primary goals was supporting biodiversity. The site hosts a huge variety of fauna, including birds, reptiles, amphibians, and beneficial insects like praying mantises, bees, and butterflies. It supports a very large population of Eastern bluebirds. “They’re all over,” Greenspan said.

One reason for the recovered biodiversity is that the team, working with river experts, restored the site’s stream system, which had been degraded by prior development. The streams are now shallower and wider, with rocky beds instead of mud, and with banks reinforced by boulders and logs.

Invasive plants
A backyard prairie a the home of Drew Lathin

In addition to native plantings, bird houses and other types of nesting boxes can help attract native fauna.

Photo: Drew Lathin

With so much land to care for, how is the museum controlling invasives? With strictly organic methods and no herbicides—unless you count vinegar. “It is a very difficult process with some of the invasive species that you get,” according to Greenspan. Initially, in consultation with landscape designer and ecologist Weaner, the team allowed weed seeds to germinate and then smothered them through a process called “solarization,” which entails covering the area with black plastic to kill off both plants and seeds.

Invasives can still appear, though, so the team has had to be strategic about managing them. One damp area rife with Japanese stilt grass was converted to a wetland, which made the grass less resilient and allowed native irises and lizard’s tail to successfully compete. Getting rid of the stilt grass up the hill from this wetland is an ongoing battle involving removal of the invasive and planting of aggressive and resilient native species.

The pavilion buildings were specifically designed to interact with the natural environment outside. One feature is a water court designed as a native wetland. Unlike with the sweeping views in other areas, “here it’s almost like looking under a magnifying glass,” said Greenspan.

Case Study: An Oasis in a Suburban Desert

Home of Drew Lathin; Novi, Michigan

“We can do better than hostas” could be Drew Lathin’s motto. As a landscape designer, he often gets calls from potential customers asking what to plant in shady spots, and that is his answer. A native woodland landscape provides a whole habitat that is “beautiful to people and beautiful to wildlife,” he told BuildingGreen.

Lathin has designed his own property, in the middle of what he describes as “a soulless, sterile suburb” to demonstrate what can be accomplished with mostly native plants. From woodlands to wetlands, the site takes advantage of existing drainage patterns, roof runoff, and other features.

Plant communities

Matrix planting is the foundation of Lathin’s style. This involves layering species and planting them densely to help prevent weeds without the need for mulch. “The more ground you take up, the fewer weeds you’re going to have,” he pointed out. For example, he uses a sedge or grass as the bottom layer, and then taller plants, including perennial flowers, can “pop up through it.”

In one matrix planting, Lathin has paired wild strawberries with cinquefoils as the base layer. If the weather is wet, the strawberries flourish, and if it’s dry, they go dormant and the cinquefoils flourish: either way, there’s a dense, weed-suppressing groundcover.

Another principle is to keep the number of species in the matrix fairly low and strategically selected so they’re not competing too much for light and water.

A rain garden at the home of Drew Lathin

Rain gardens manage drainage on Lathin’s property.

Photo: Drew Lathin

Working with (and without) water

One remarkable feature of Lathin’s site is that he has not made major changes to its drainage patterns to accommodate his planting whims: instead, he has based his garden plans on what the water was already doing.

One raingarden captures runoff from the roof, while another soaks up moisture from a damp place bordering the neighbor’s property. A bioswale also helps manage runoff there.

Lathin’s sump pump used to drain into a storm sewer, but rather than wasting that precious liquid, he has diverted it to create a pond planted with species that prefer standing water. It’s all about putting the right plant in the right place, he says. “The lesson here is that you don’t need to change drainage patterns. Use plants that like to live in the conditions that you have.”

A backyard prairie

Lathin is gradually taking over other pieces of land in his suburb—with permission, of course. The raingarden on the border is actually in the neighbor’s yard. Another neighbor, who had been mowing a 2,000-square-foot patch of turf for years, agreed to let Lathin seed a prairie instead. He has rid the area of invasive smooth brome and replaced that with native beardtongue, spiderwort, and golden Alexanders.

Finally, he has done a little guerilla gardening by removing garlic mustard in a narrow area next to a shed on the other side of his fence and flinging native seeds in instead, just to see what grows.

Lathin cautions that with native plants, you sometimes have to wait in order to see your landscape flourish. He talks about a three-year process of “sleep, creep, and leap”: for the first year, the plants establish a strong root system and might not look like much; in the second year, they begin to pop up and flower; and in the third year, “they just explode.” This isn’t like what happens with what he calls big horticulture. “You’re not getting a big plant fed to the nines” that allows you to “put plants in the ground, do a 360, and you have a mature landscape. That’s just not the case with natives.”

Google green loop

The “Green Loop” on Google’s Mountain View campus is a 7.9-mile biking and walking path featuring native plantings.

Photo courtesy Google Ecology Program

Case Study: Searching for Habitat

Google’s Bay Area campuses

Ecologists spend a lot of their time outdoors, of course, but certain activities take place in the archives. Historical photographs, maps, soil and topographic surveys, and other documents unearthed and analyzed by Grossinger and his team at the San Francisco Estuary Institute “are a backbone of our work,” said Daniel Stephens, principal at ecological consulting company H.T. Harvey and Associates, a contractor with Google.

That’s because the Google team is looking to be “inspired by history to understand what's changed, what's stayed the same, and what might be appropriate for current and future conditions”—including resilience to climate change—according to Erin Beller, Ph.D., ecology program manager for Google’s Real Estate and Workplace Services Sustainability Team.

Supercharging biodiversity

“We’re not just thinking about native plants,” noted Beller. “We’re thinking about creating ecosystems and habitats.” The efforts “got supercharged due to the scale jump Google was experiencing” in the mid-2010s, when the company realized it had “an opportunity and a responsibility to be thinking beyond the 1980s office-park building and really at the campus scale. It was an opportunity for real, meaningful ecology,” said Beller.

The work began in 2014 around the company’s Bay Area offices and is already attracting diverse wildlife, from birds like the oak titmouse and lesser goldfinch to a variety of native bees and butterflies. Google is now starting to pilot urban ecology projects in other bioregions around the world. Beller said her job as the Ph.D. in the room is to provide the kind of support that results in “critical performance co-benefits—like wildlife support, heat and flood reduction, and human health—not just pretty outdoor landscapes.”

Google campus with native plantings

Google employees can enjoy the native plantings outdoors during the work day.
 

Photo courtesy Google Ecology Group

Restored ecosystems, like riparian habitats and oak woodlands, provide breathing space for both wildlife and people. “We do a lot of work designing trails that meander, have bulges and benches—invitations to stop and enjoy what’s there,” said Stephens. “We’re trying to support an immersive experience.” At the same time, the goal is to catalyze biodiversity—not just expand the population of the same old scrub jays. In turn, this diversity creates a “richer biophilic experience” for people, according to Stephens.

Let it grow

Because of the dual goal of these landscapes, maintenance can sometimes be a tricky balance. Maintenance crews have been specially trained to care for the natural areas without manicuring them. This means, for example, not trimming bushes as much, letting seed heads complete their full growing cycle, and leaving bare soil patches instead of mulching because some bird species like to forage there. Additionally, the contractors maintain the areas people frequent—near paths and buildings—more aggressively than habitat areas farther from human interactions; the deeper into the habitat you get, the wilder it is. People occasionally want to know why the landscape looks the way it does, Stephens told BuildingGreen. But once you explain, there is a very quick “conversion” to comments like, “This is pretty cool; I love seeing all the hummingbirds.”

Going public

Besides providing restorative space for wildlife and humans, Google’s ecological restoration work may have benefits beyond its campuses. “We develop a lot of technical documentation that’s internal,” said Stephens. “But we’re working to transform that into open-source documents available to everybody.” One of the first is a set of design guidelines for urban landscapes.

Case Study: Little Factory on the Prairie

Keson Industries; Aurora, Illinois

Keson Industries turf before prairie

This “before” picture shows the expensive-to-maintain turf on the property of Keson Industries.

Photo: Ron Nosek
Ron Nosek has been a lover of the outdoors and an environmentalist for as long as he can remember. So 15 years ago, he asked himself why he was “paying a landscaper to mow … four acres and fertilize it and pollute the air and make a lot of noise and waste gasoline and have runoff to the retention pond” on the land where his family has a manufacturing facility. Bereft of an answer, Nosek began his search for a landscape architect who could help him plant those four acres with low-maintenance natives. He found Pizzo through his local land conservation foundation.

In 2006, Pizzo designed and seeded a prairie, hosting 36 varieties of wildflower and 13 varieties of prairie grass, that’s tucked between the property’s retention pond and a forest preserve. The factory itself, where measuring tools are manufactured, takes up the other four acres of the land.

Succession and maintenance

Over the years, as tends to happen with native landscapes as they mature, the prairie has changed. “Ours has a mind of its own,” says Nosek. “Some of the things—the bright and showy coneflowers and butterfly weed—they’re not there anymore. Other things have taken over. A good third of the prairie is primarily grasses.” Additionally, buckthorn, holly, and other aggressive plants try to invade, which means Nosek spends a lot of time in the field dealing with those.

 Keson Industries prairie

This “after” picture shows the low-maintenance prairie that takes up four acres of the Keson Industries property.

Photo: Ron Nosek
As for the cost of mowing and fertilizing, Nosek told BuildingGreen he has saved $75,000 in landscaping fees since 2006. He does do much of the prairie maintenance (which consists mostly of managing invasives and preventing trees from taking over the grasslands), but he said that paying Pizzo’s crew to steward the land would cost $1,700 per year. Meanwhile, he had formerly been spending $5,000 a year on maintaining turf.

Published August 2, 2021

Wilson, A., & Melton, P. (2021, July 19). Native Landscaping for Biodiversity. Retrieved from https://www.buildinggreen.com/feature/native-landscaping-biodiversity

Continuing Education

Upon completion of this course, participants will be able to:

  1. Understand the importance of biodiversity and ecosystem services to supporting human life on Earth.

  2. Explain why even small patches of native landscaping can support biodiversity and improve environmental performance.

  3. List 13 strategies for using native plantings to prevent species loss and to improve environmental performance in other ways.

  4. Discern the most effective ways to manage invasive plants to protect native species.

Comments

August 19, 2021 - 2:57 pm

This is a great article - I hope all designers AND facility managers should read and act. Glad you included the short discussion aout "restorative spaces for humans" and thin that in follow up conversations you could talk the about health, reduced crime and reduced stress levels of plants and trees, especially in an urban setting.

August 23, 2021 - 9:23 am

Good point about urban plants and trees.